DETERIORATE; be -, become- -worse, - deteriorated &c. adj.; have seen better days, degenerate, fall off; wane (decrease) [See Nonincrease, Decrease]; ebb; retrograde [See Regression]; decline, droop; go down (sink) [See Descent]; go downhill, go on from bad to worse, go farther and fare worse; jump out of the frying pan into the fire; avoid Scylla and fall into Charybdis.
run to -seed, - waste; swale [obs.], sweal [obs.]; lapse, be the worse for; sphacelate; break, break down; spring a leak, crack, start; shrivel (contract) [See Contraction]; fade, go off, wither, molder or moulder, rot, rankle, decay, go bad; go to -, fall into- decay; fall into the sere, the yellow leaf [Macbeth]; rust, crumble, shake; totter, - to its fall; perish [See Destruction]; die [See Death].
[RENDER LESS GOOD] deteriorate; weaken [See Weakness]; put back; taint, infect, contaminate, poison, empoison, envenom, canker, corrupt, exulcerate [obs.], pollute, vitiate, inquinate [obs.], debase, embase [obs.]; denaturalize, leaven; deflower, debauch, defile, deprave, degrade; ulcerate; stain (dirt) [See Uncleanness]; discolor; alloy, adulterate, sophisticate, tamper with, prejudice.
PERVERT, prostitute, demoralize, brutalize; render vicious [See Vice].
EMBITTER, acerbate, exacerbate, aggravate.
INJURE, impair, labefy [rare], damage, harm, hurt, shend, scath [dial.], scathe, spoil, mar, despoil, dilapidate, waste; overrun; ravage; pillage [See Stealing].
wound, stab, pierce, maim, lame, surbate [obs.], cripple, hock or hough, hamstring, hit between wind and water, scotch, mangle, mutilate, disfigure, blemish, deface, warp.
BLIGHT, rot; corrode, erode; wear away, wear out; gnaw, - at the root of; sap, mine, undermine, shake, sap the foundations of, break up; disorganize, dismantle, dismast; destroy [See Destruction].
DAMNIFY (aggrieve) [See Badness]; do ones worst; knock down; deal a blow to; play -havoc, - sad havoc, - the mischief [colloq.], - the deuce [colloq.], - the very devil [colloq.]- -with, - among; decimate.
DETERIORATED &c. v.; altered, - for the worse; unimproved &c. (improve [See Improvement]); injured &c. v.; sprung; withering, spoiling &c. v.; on the -wane, - decline; tabid; degenerate; worse; the -, all the- worse for; out of -repair, - tune; imperfect [See Imperfection]; the worse for wear; battered; weathered, weather-beaten; stale, passé [F.], shaken, dilapidated, frayed, faded, wilted, shabby, secondhand, thread- bare; worn, - to- -a thread, - a shadow, - the stump, - rags; reduced, - to a skeleton; far-gone; tacky [colloq. or slang].
DECAYED &c. v.; moth-eaten, worm-eaten; mildewed, rusty, moldy or mouldy, spotted, seedy [colloq.], time-worn, moss-grown; discolored; effete, wasted, crumbling, moldering or mouldering, rotten, cankered, blighted, marcescent, tainted; depraved (vicious) [See Vice]; decrepit; broken-down; done, - for, - up [all colloq.]; worn-out, used up [colloq.]; fit for the -dust hole, - waste-paper basket; past work (useless) [See Inutility].
AT A LOW EBB, in a bad way, on ones last legs; undermined, deciduous; nodding to its fall (destruction) [See Destruction]; tottering (dangerous) [See Danger]; past cure (hopeless) [See Hopelessness]; washed out, run down; fatigued [See Fatigue]; unprogressive, improgressive [rare], backward, stagnant, behind the times; retrograde (retrogressive) [See Regression]; deleterious [See Badness].
ON THE DOWN GRADE, on the downward track; beyond hope.
What a falling off was there!Hamlet
Oh, what a fall was there, my countrymen!Julius Cæsar